Learnist is a new site that is still in beta but looks promising. The site allows you to create "Learn Boards" on any topic you want to and then add "learnings" by linking to websites, online videos, blogs, images, documents, etc. It is similar to Pinterest in some ways. You can also collaborate with others on the same board.

You can search for existing Learn Boards by topic and search term. Here are some from "Education":